The Tecumseh study of respiratory illness. V. Patterns of infection with the parainfluenzaviruses.

Monto, A. S. (Dept. Epidem., Sch. Public Health, Univ. Michigan, Ann Arbor, Mich. 48104). The Tecumseh study of respiratory illness. V. Patterns of infection with the parainfluenzaviruses. Am J Epidemiol 97: 338–348, 1973.—Patterns of parainfluenzavirus infection during the 6 years of the Tecumseh study of respiratory illness were examined. Type 3 was isolated most frequently and type 4, least. Although most isolates were recovered from children under the age of 10 years, 23% of the strains were isolated from older individuals. The type of illness associated with virus isolation appeared to be more severe than that encountered with rhinovirus infections. Type 3 was endemic in occurrence; type 2 was limited to relatively short periods of prevalence but the pattern of type 1 isolation changed during the study. Types 1 and 3 were isolated most frequently in the fall, and type 2 in winter. Testing of 2819 sera collected routinely from persons on surveillance confirmed the periodicity of infection with types 1, 2 and 3. Infections with type 3 clearly occurred more frequently early in life than types 1 and 2. For the latter two types, serologic infection rates were highest in the 5 to 9 year age group. The rate per person-year for the entire population studied was 28.6% with types 1, 2 and 3 combined. It is, therefore, conduded that these infectious agents are among the most frequently encountered respiratory pathogens of man.